1. Field of the Invention
The present invention relates to an auto-dialing apparatus which stores telephone number data in a memory, reads out the telephone number data when a switching operation or the like is performed, converts the readout telephone number data into a dialing tone signal, and outputs the dialing tone signal.
2. Description of the Related Art
Conventionally, apparatuses for converting a telephone number into a dialing tone and outputting the dialing tone are known, and are described in, e.g., U.S. Pat. Nos. 4,087,638 and 4,563,548. An auto-dialing apparatus is also known. In this apparatus, a plurality of names and telephone numbers are stored in a RAM memory, and when one of the plurality of names is selected, a telephone number corresponding to the selected name is read out from the RAM memory and converted to a dialing tone signal and tones corresponding to the dialing tone signal are produced. Thus, a telephone call can be made without depressing push buttons of a telephone set. This apparatus is disclosed in, e.g., U.S. Pat. Nos. 4,117,542 and 4,769,836.
When a telephone call is to be made using an apparatus of this type, names and telephone numbers in the RAM memory are sequentially displayed on a display unit. An operator brings a speaker of the apparatus into contact with a handset and causes the speaker to output dialing tones while a desired name and telephone number are displayed. With the apparatus of this type, since dialing tones must be sent through a handset, if the apparatus is bulky, the dialing operation is very cumbersome. Since the apparatus of this type is often meant for an outdoor use, it must be made compact to improve portability.
The number of digits of a domestic (Japanese) telephone number is a maximum of about 10, and that of an international telephone number is about 12. In an international telephone number, the number of division data for dividing a subscriber's number and a trunk code, or the like is five. In order to store and display an international telephone number including such division data, a storage unit and a display unit having about 17 digits are necessary.
For this reason, in a conventional apparatus for displaying the entire telephone number, the number of display digits is too large, and a display space cannot be reduced. As a result, the display unit becomes large in size, and the auto-dialing apparatus itself cannot be made compact.
In recent years, some telephone service companies provides services for a credit call. In a credit call system, a telephone number and an identification number (password) are registered in a telephone service company, and telephone charges are paid at a later time. In the case of a credit call, an access number to the telephone service company, a number for specifying a caller or a telephone number of a caller, a password, and the like must be dial-input in addition to a telephone number of a callee. Therefore, when a credit call is to be made using the auto-dialing apparatus, the telephone numbers and the identification numbers must be prestored. However, in the conventional auto-dialing apparatus, a storage capacity enough to perform a credit call is not assigned to one telephone number. Thus, the conventional auto-dialing apparatus cannot cope with a credit call. A storage capacity capable of storing various numbers necessary for a credit call may be assigned to each telephone number data. In this case, however, a portable compact auto-dialing apparatus having a limited total storage capacity must inevitably reduce the number of telephone number data to be stored. When various telephone numbers are additionally stored in units of telephone number data, since the various telephone number portions are the same for any telephone number data, the storage unit is very wastefully used.
Such a drawback occurs not only in a credit call but also in, e.g., an international call since an international telephone identification number, national number, or the like must be set.